[TASK] Don't try to create language switch for non-persisted records

The language switch is never rendered for non-persisted records,
so the method to create it should not be called in this sitation.

Resolves: #92971
Releases: master, 10.4
Change-Id: If6d85a7bbf44a841f08d0331da3e5e0943232953
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/66962

Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/backend/Classes/Controller/EditDocumentController.php

@@ -1016,11 +1016,15 @@ class EditDocumentController
         }
         // Setting up the buttons and markers for doc header
         $this->getButtons($request);
-        $this->languageSwitch(
-            (string)($this->firstEl['table'] ?? ''),
-            (int)($this->firstEl['uid'] ?? 0),
-            isset($this->firstEl['pid']) ? (int)$this->firstEl['pid'] : null
-        );
+
+        // Create language switch options if the record is already persisted
+        if ($this->isSavedRecord) {
+            $this->languageSwitch(
+                (string)($this->firstEl['table'] ?? ''),
+                (int)($this->firstEl['uid'] ?? 0),
+                isset($this->firstEl['pid']) ? (int)$this->firstEl['pid'] : null
+            );
+        }
         $this->moduleTemplate->setContent($body);
     }